Researchers said the finding could help identify a cause and a new way to treat people who have the disease.
There are well-defined genetic patterns within the brains of all autism patients, no matter their symptoms, according to scientists who say the finding may help identify a cause and a new way to help patients.
The patterns are seen in the way genes are expressed to create proteins in the brain, according to a paper published online Wednesday in the journal Nature. Distinct similarities were seen among autistic brains in areas that play a role in judgment, creativity, emotions and speech, the report said. Brains of those without the disease showed different patterns.
Developmental disorders, including autism, have increased 17 percent from 1997 to 2008, researchers said this week. "Several of the genes that cropped up in these shared patterns were previously linked to autism," said Daniel Geschwind, a professor of neurology and psychiatry at the University of California Los Angeles medical school and a study author. "We provide evidence that the common molecular changes in neuron function and communication are a cause, not an effect, of the disease."
Autism is a developmental disorder that appears in the first 3 years of life and affects the brain's normal development of social and communication skills.
Scientists compared brain samples from 19 deceased autism patients and 17 healthy volunteers to measure gene expression levels. The autistic brains studied didn't have as many genes responsible for neuron communication as normal organs, and they had more DNA involved in immune function, the study found. In healthy controls, 500 genes varied in expression between the frontal lobe, the control center for judgment, and the temporal lobe, which organizes sensory input, the researchers found. In the autistic brains, there was no difference between these regions.
The team included scientists from the University of Toronto and King's College London.